Does these 3 queries give the same result?

Question

1. select * from table_name
where not column_name = 'value';

2. select * from table_name
where column_name <> 'value';

3. select * from table_name
where column_name != 'value';

Answer 1

Cause <> and != are the same operator (not equal) in the dB engines which support both.
And not(a=b) is equivalent to a<>b.

Answer 2

Yes, this should give the same result.